Work machines which carry material are subject to wear through the movement of material in the body of the machine. For example, an off-highway truck typically has a material-carrying body which can be moved to an upright position to eject the material through an opening in the body. This wear is particularly aggravated, for example, by the sliding of material across the portion of the bed or floor adjacent the rear opening from which the material is ejected. Other trucks for hauling and dumping may have similar problems with wear.
In an attempt reduce wear, many solutions have been tried. For example, sheets of material as liners are sometimes added to a truck body to provide additional protection. To increase the durability of such sheets, the entire surface of the sheet has been provided with a durable cladding of abrasion-resistant chromium carbide material. However, such liners are still subject to the same high wear of sliding materials as the truck bodies they protect since they have a substantially smooth upper surface, which permits the materials to slide from the body. Another solution has been to attach bars to the bed or floor of a truck body in rows across the width of the bed. Similarly, a cross hatch of plates approximately two inches high have been added to provide "boxes" on the bed of the truck. The bars or boxes cause material to tumble instead of slide as it moves across the truck bed be ejected from the rear opening. This tumbling motion reduces wear by tending to eliminate the high wear characteristics of sliding material. However, these so-called tumbler bars or boxes require a considerable amount of welding to attach, involve the handling of a large number of different parts, are limited in the way they can be attached (typically only by conventional welding) and are susceptible to breaking loose. If they do break loose, the metal parts can be ejected from the truck body into another material handling device, such as a rock crusher, and cause damage to that device.
One known solution to the problems presented by tumbler bars or boxes is to use a liner plate of hard steel having a pattern of openings cut therethrough. The openings through the liner plate cause material exiting the body to tumble as they pass thereover and also trap fines, both of which reduce wear on the liner plate. However, such a liner plate is advantageously formed from hard steel, e.g. 400 to 500 Brinell hardness, which does not lend itself to welding due to the difficulty of preheating the steel sufficiently. As a result, fasteners, such as bolts or rivets, may be needed to secure the liner plate to the machine body.
This invention is directed to overcoming one or more of the problems set forth above.